Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuinely useful behavior beyond that: results are watermarked previews, never originals, with fixed prices attached, and the query engine tolerates typos and supports English or French. It omits ranking/pagination behavior, which keeps it out of 5 territory.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, zero filler. The core capability comes first, the return contract second, and the licensing constraint last, which is exactly the order an agent needs it.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only search tool with no output schema, the description covers the return payload, the language/tolerance behavior, and the licensing limit. Remaining gaps (result ordering, how offset interacts with limit) are minor and partly covered by the schema descriptions.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the schema already documents all five parameters (limit, offset, query, country, category). The description still adds meaning the schema does not: the query field tolerates synonyms, typos and both English and French, which changes how an agent should phrase queries.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Search the catalogue') and describes the return payload (watermarked previews, metadata, fixed prices), which implicitly separates it from get_photo and get_download_link. It never names a sibling explicitly, so the differentiation is inferable rather than stated.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies a discovery use case ('Empty = best photos', search tolerance for typos) but never says when to choose this over get_photo for a known asset or get_quote for pricing. Usage is implied by the described output, not spelled out as when/when-not guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.